| A | B |
|---|
| Ion | An atom or group of atoms that is electrically charged |
| Ionic Bond | The attraction between two oppositely charged ions |
| Polyatomic Ion | An ion that is made of more than one atom |
| Crystal | An orderly, three-dimensional pattern of ions or atoms in a solid |
| Covalent Bond | A chemical bond formed when two atoms share electrons |
| Double Bond | A chemical bond formed when two atoms share two pairs of electrons with each other |
| Molecular Compound | A compound consisting of molecules of covalently bonded atoms |
| Polar | The description of a covalent bond in which electrons are shared unequally, or of a molecule containing polar bonds that do not cancel out |
| Nonpolar | The description of a covalent bond in which electrons are shared equally, or of a molecule containing nonpolar bonds or polar bonds that cancel out |
| Mineral | A naturally occurring solid that has a crystal structure and a definite chemical composition; a simple element, which is not organic, that is needed by the body |
| Nuclear Reaction | A reaction involving the particles in the nucleus of an atom that can change one element into another element |
| Isotope | An atom with the same number of protons and different number of neutrons from other atoms of the same element |
| Mass Number | The sum of the protons and neutrons in the nucleus of an atom |
| Radioactive Decay | The process in which the atomic nuclei of unstable isotopes release fast moving particles and energy |
| Nuclear Radiation | Particles and energy produced during radioactive decay |
| Alpha Particle | A form of nuclear radiation consisting of two protons and two neutrons |
| Beta Particle | An electron that is given off by a nucleus during radioactive decay |
| Gamma Radiation | A form of nuclear radiation consisting of high-energy waves |
| Half-life | The length of time needed for half the atoms of a radioactive isotope sample to decay |
| Radioactive Dating | The process of determining the age of an object using the half-life of one or more radioactive isotopes |
| Tracer | A radioactive isotope that can be followed through the steps of a chemical reaction or industrial process |
| Radiation Therapy | A process in which radioactive elements are used to destroy unhealthy cells |
